EP0292428B1 - System mit Band-Anode für den kathodischen Schutz von stahlarmiertem Beton - Google Patents

System mit Band-Anode für den kathodischen Schutz von stahlarmiertem Beton Download PDF

Info

Publication number
EP0292428B1
EP0292428B1 EP88810287A EP88810287A EP0292428B1 EP 0292428 B1 EP0292428 B1 EP 0292428B1 EP 88810287 A EP88810287 A EP 88810287A EP 88810287 A EP88810287 A EP 88810287A EP 0292428 B1 EP0292428 B1 EP 0292428B1
Authority
EP
European Patent Office
Prior art keywords
ribbon
anode
concrete
cathodic protection
protection system
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP88810287A
Other languages
English (en)
French (fr)
Other versions
EP0292428A3 (en
EP0292428A2 (de
Inventor
Barry L. Martin
John E. Bennett
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Eltech Systems Corp
Original Assignee
Eltech Systems Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Eltech Systems Corp filed Critical Eltech Systems Corp
Priority to AT88810287T priority Critical patent/ATE72840T1/de
Publication of EP0292428A2 publication Critical patent/EP0292428A2/de
Publication of EP0292428A3 publication Critical patent/EP0292428A3/en
Application granted granted Critical
Publication of EP0292428B1 publication Critical patent/EP0292428B1/de
Priority to SA92130118A priority patent/SA92130118B1/ar
Expired legal-status Critical Current

Links

Images

Classifications

    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
    • E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
    • E04B1/62—Insulation or other protection; Elements or use of specified material therefor
    • E04B1/64—Insulation or other protection; Elements or use of specified material therefor for making damp-proof; Protection against corrosion
    • E04B1/642—Protecting metallic construction elements against corrosion
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
    • C23F13/02—Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F2201/00—Type of materials to be protected by cathodic protection
    • C23F2201/02—Concrete, e.g. reinforced

Definitions

  • slotted non-overlay anodes were developed to provide an approach that would not increase the dead load and height of the concrete structure.
  • the slots can be filled with a "conductive grout" mixture of carbon and organic resin which serves as the anode surface. Because the conductive grout has a limited conductivity, current is distributed to the anode by a system of platinized metal wire and carbon strand conductors.
  • Valve metal electrodes as typified by expanded titanium mesh have recently gained wide acceptance for application over a broad expanse of steel-reinforced concrete.
  • Such electrodes as detailed in EP-B-0 222 829 can readily cover broad surfaces. They are most advantageous when rolled out on such a broad surface as a flat bridge deck. Such broad coverage has lead to the acceptance of this type of cathodic protection system. When installed, the system is provided with an entire cover overlay. Such system thus not only requires a broad cover overlay but may also require some adjusting to work around obstructions.
  • the invention is directed to an impressed-current cathodic protection system for steel reinforced concrete, which system comprises :
  • Fig. 1 is a perspective view of a portion of a concrete structure underside receiving a cathodic protection ribbon anode.
  • Fig. 2 is a perspective view of a portion of a concrete structure receiving cathodic protection around an obstruction.
  • Fig. 3 is a perspective view of a reinforced concrete bridge support structure having ribbon anodes in place.
  • Fig 4. is a perspective view of a portion of a ribbon anode assembly on edge for installation in a slotted reinforced concrete structure.
  • Fig. 5 is an overhead view of a slotted reinforced concrete structure of a bridge deck or the like being prepared for the assembly of Fig. 4.
  • this invention will find utility in any application where a reinforced concrete structure is in need of cathodic protection and presents a surface, horizontal, vertical, inclined or overhead, for system application.
  • the invention will find utility for application directly on a surface or where slots can be cut into the surface of the structure.
  • the invention will find particular utility on vertical or overhead surfaces where complete coverage of an existing structure with a cementitious overlay is undesired or will be impractical.
  • the protection system of the present invention will find use in steel reinforced concrete structures such as bridge decks, parking garage decks, bridge substructures and building structural members.
  • a reinforced concrete structure shown generally at 31, receiving cathodic protection on the underside.
  • an imperforate anode ribbon 32 feeding from a source such as a coil of ribbon, not shown, is applied to the underside 33 of the concrete structure 31 such that one face of the anode ribbon 32 is applied to the surface of the concrete structure 31.
  • the ribbon 32 may be initially fastened into the steel reinforced concrete structure 31 such as plastic or other non-conductive fasteners which may be inserted into drilled holes or glued to the structure surface.
  • a bead 35 of ionically conductive cementitious material This bead 35 covers the face of the anode ribbon 32 that is left exposed at the underside 33.
  • the sprayer 34 can deliver a sufficient bead 35 to embed the anode ribbon 32, but need not cover the entire surface of the underside 33.
  • a portion of a concrete structure such as the edge of a parking garage deck is shown generally at 41.
  • This structure 41 has a floor 42 and a side wall 43.
  • the edge between the floor 42 and side wall 43 is interrupted by an obstruction, as shown in the drawing in this case a standpipe 44, which runs along the side wall 43 and protrudes through an aperture in the floor 42.
  • anode ribbon 45 For receiving cathodic protection for the floor 42, there is initially applied, such as from a coil, not shown, and anode ribbon 45.
  • the anode ribbon 45 readily lends itself to application on the floor 42 around the standpipe 44 by being at first readily bendable back on itself by 180°.
  • the ribbon 45 that is bent back can be twisted perpendicular to its longitudinal axis at 90° angles to form ribbon anode corners 46.
  • the anode ribbon 45 such can then be embedded in an ionically conductive cementitious material, not shown, as in the manner shown in Fig. 1.
  • FIG. 3 there is depicted a reinforced concrete support structure, viewed from underneath, shown generally at 51.
  • This structure 51 has a vertical surface 52, rounded at the end, as well as an underneath flat underside surface 53.
  • Anode ribbon 54 is applied by wrapping around the vertical surface 52 and can initially, during application, be fastened to the underlying vertical concrete surface 52, such as by plastic fasteners.
  • the ribbon is initially applied as a flat section 55.
  • the preceding flat section 55 of the ribbon is twisted on its longitudinal axis at an approximately 90° angle whereby the corner end of the anode ribbon 55 forms an edge section 56.
  • the anode ribbon 55 is initially in face contact with the concrete structure 53, but in twisting the ribbon 55 by 90° along the longitudinal axis to accomodate for the corner, it is in edge contact with the concrete structure. As the path of ribbon 55 extends around the corner, the ribbon 55 twists back 90° along its longitudinal axis back into face contact with the concrete structure 53. It is to be understrood however that the anode ribbon could be tailored to the corner by many flat folds, rather than twisted on edge. All of the applied anode ribbons can then be embedded in an ionically conductive cementitious material, not shown, such as in the manner taught in Fig. 1.
  • an anode ribbon system of the present invention is shown, in part, generally at 10.
  • This anode ribbon system 10 has individual anode strips or ribbons 2 which are to be set in slots in concrete (not shown). These anode ribbons 2 are spaced apart one from the other at least in substantially parallel configuration.
  • the anode ribbons 2 have ribbon end sections 3. As shown in the Figure, these ribbon end sections 3 can be readily formed because the ribbon configuration provides for ease of bending the ribbons back on themselves at a 90° angle so that the end sections 3 can be a continuation of the anode ribbons 2. The overall effect is a continuous strip anode with the anode ribbons 2 continuing into ribbon end sections 3 and so on.
  • the ribbon end sections 3 are adjoined to a current feeder 4. For good electrical contact between the ribbon end sections 3 and current feeder 4 such can be joined by spot welds 5.
  • the current feeder 4 can then be connected, by means not shown, to a source of impressed current.
  • FIG. 5 an overview of a slotted, steel reinforced concrete structure is shown generally at 20.
  • the concrete surface 12 has current feeder slots 13 cut therein. This surface 12 as thus prepared is then ready for insertion of anode ribbons and current feeders.
  • the cuts will be placed so as to provide an at least somewhat equidistant spacing between cuts thereby providing evenness to the current discharge over the total protected surface.
  • the distance between applied ribbon anodes 54, or between slots 11, will be at least about 15 centimeter (cm.) for economy while such spacing will usually not exceed above about 60 cm. to insure an even current distribution to the reinforcing steel.
  • Most typically the spacing between adjacent ribbons, in surface applications as in cuts, will be within the range from about 25 to about 40 cm.
  • anode ribbons 2 have a width of about 2.5 cm. or less. Although, for convenience, usually only the anode ribbons 2 will be referred to hereinafter it is to be understood that such references are meant to include any and all of the anode ribbons 2, 32, 45 and 54.
  • An anode ribbon 2 of greater than about 2.5 cm. width is uneconomical.
  • an anode ribbon 2 having a width of less than about 0.25 cm. will require an uneconomical number of closely spaced ribbons or slots 11.
  • such anode ribbon 2 will usually have a thickness of about 0.15 cm.
  • the anode ribbon 2 for adequate distribution of current along the anode ribbon 2, will have a thickness of at least about 0.02 cm.
  • the anode ribbon 2 will most always have a width of on the order of from about 0.5 to 0.8 cm. and a thickness of from about 0.05 to about 0.08 cm.
  • the ribbon anode has a ribbon width at least substantially greater than its thickness. Furthermore, it will have a ribbon length at least substantially greater than its width, e.g., as shown in the figures. As supplied in the field for installation, the anode ribbon will frequently be in coil form, for efficiency of storage and handling. Typically such coils will contain a length of from 100 meters to 200 meters of anode ribbon, or more, although shorter length coils, e.g., of 10 to 50 meters of anode ribbon, may be serviceable. With regard to thickness and width, the ribbon anode can be expected to have a width to thickness ratio within the range from about 20:1 to about 5:1.
  • the ribbon configuration provides an advantageous aspect ratio, i.e., a high ratio of anode surface area to anode length.
  • the dimensions for the ribbon anode as above discussed provide for an anode which can be readily bent back on itself, e.g., initially at a 90° angle as depicted in Fig. 4 or at a 180°, angle and rotated in its plane of application as depicted by the corners 46 in fig. 2.
  • This provides for desirable ease of application of the anode during installation, e.g., in rectangular patterns as depicted in figs. 4 and 5 or around corners or obstructions which can often occur on a concrete surface as depicted in Fig. 2.
  • the ribbon anode will have desirable ease of twisting along its longitudinal axis, such as to the extent as depicted in the underside surface 53 in Fig.
  • the anode may be twisted around corners to a 90° angle and thereby interface on its edge to the underlying concrete surface.
  • the ribbon anode can again resume a more usual flat surface contact with the concrete surface. It is however to be understood that especially when the ribbon anode has an active coating on both flat faces, that the entire installation can contain the ribbon anode mounted on its edge on the concrete surface. If applied on edge or at an angle, the resulting height of an anode of maximum width will be at most about 2.5 cm., which can readily be covered by cementitious material. Typically a layer of such material of from about 3 to about 5 cm.
  • a layer of cementitious material of at least about 1.2 cm., up to about 3 cm. thickness, will usually be applied, e.g., where the ribbon anode is utilized on an overhead or vertical surface.
  • Such anode ribbons 2 corresponding to these dimensions will readily handle operative current densities of 200 milliamps per square meter (mA/m2) of anode area without damage to surrounding concrete. It is contemplated that the current densities in operation may be on the order of at least about 50 mA/m2 and such anodes 2 as described herein will efficiently carry such loads while maintaining current distribution uniformity. It is however to be understood that current densities on the order of about 400 to 600 mA/m2 or more are contemplated, although densities on the order of 100-300 mA/m2 will be most advantageous for best steel reinforcement corrosion protection.
  • the anode ribbon slots 11 are thus cut of sufficient width and depth to provide for ease of installation of the ribbon 2.
  • a slot depth of on the order of about 1.25 to about 2.5 cm. will be typical. More usually, such a slot 11 will be cut to a depth of on the order of 1 cm. or less, e.g., 0.6-0.8 cm.
  • the anode slot 11 will typically be cut to a depth exceeding the anode ribbon width by about 0.5 to 1.0 cm., e.g., to a depth not exceeding about 2.5 to 4 cm.
  • a single saw blade cut a slot of about 0.3 cm. width will be prepared.
  • This can be serviceable for anode ribbon 2 insertion, but for best ease of backfilling, such as with pumpable grout, two blades are most always ganged together so that a slot of about 0.6 cm. will be cut, although ganging up to provide slot widths of about 1.25 cm. may be utilized.
  • the current feeders 4 can also be inserted into slots 13. These slots can likewise be saw cut into the concrete surface.
  • such feeders 4 may generally be essentially equally spaced from one another, although it is not as necessary that the current feeders 4 be equidistant from one another, as it is for the anode ribbons 2.
  • adjacent ribbons will usually run parallel to each other, although other configurations are contemplated.
  • the distance between current feeders 4 may be as great as about 100 meters, while for more elevated current densities such distance should be reduced to on the order of 25 to 30 meters.
  • current feeders will be spaced apart on the order of from about 50 to about 80 meters.
  • the current feeders are also advantageously in elongated form of at least substantially ribbon dimension, as such has been discussed hereinbefore. Such provide ease of attachment of the anode ribbons to the current feeder either in edge or vertical position, as shown in Fig. 5, or when both are horizontal or flat on a concrete surface.
  • other configurations for the current feeders 11 are contemplated including rods.
  • the current feeders as elongated strips will be thicker, or wider, or thicker and wider than anode ribbons, e.g., as thick as about 0.3 cm. and up to about 5 cm. wide, in order to distribute current evenly to such ribbons 2 with minimal IR voltage loss.
  • the current feeders can be twice the width or twice the thickness, or both, of the individual anode ribbons although width or thickness relationships of feeder to anode may generally range from on the order of 1.1:1 to 3:1. It will thus be appreciated that the slots 13 for the current feeders can have similar width as for the anode ribbons, and may even have similar depth, but may be more, e.g., 5 cm. deep.
  • the installation can be initiated in one method by laying out anode ribbon on the concrete, such as typically by unrolling a continuous strip of ribbon from an anode ribbon coil.
  • the anode ribbon can be laid along the concrete surface as depicted in Fig. 1 or laid into cut slots 11, as shown in Figs. 4 and 5, all in continuous manner.
  • Current feeders 4 may also be laid out at the surface of the concrete. As the anode ribbon 2 is bent to go between individual ribbon slots 11 and through the current feeder slot 13, the ribbon end section 3 can be fastened to the current feeder 4.
  • the same system may be used for flat, or horizontal, application at the concrete surface.
  • Any means suitable for providing an adherent, electrically conductive connection between the anode ribbon and current feeder may be used, e.g., crimping.
  • welding is most advantageous for efficiency and economy, e.g., roller welding and spot welding, and spot welding is preferred for best efficiency.
  • the system can be covered or may be first installed by simply slipping the anode ribbons 2 and current feeders 4 into the cut slots 11.
  • Other, alternative methods may be employed, e.g., cutting anode ribbons into essentially predetermined length, but with end tabs and then fastening the tabs to current feeders.
  • the slots 11 and 13 can then be backfilled. So long as the slots 11 and 13 have not been cut to a depth so as to jeopardize contact between the anode ribbons 2 or current feeders 4 and the steel reinforcing elements of the concrete structure, no preparation of the slots 11 and 13 before installation of the anode ribbons 2 and current feeders 4 is necessary.
  • the anode ribbons 32 need only be laid on the surface and usually fastened thereto.
  • any ionically conductive cementitious material with a volumetric resistivity of less than about 50,000 ohm-cm. will be suitable.
  • the backfill not be a conductive carbonaceous backfill or other such conductive backfill since this will result in the carbonaceous material becoming anodically active which may result in damage to the surrounding concrete.
  • Representative cementitious backfills or surface coatings that can be used include non-shrink, self-leveling and pumpable grouts, Portland cement, and other cements and will most typically have a volumetric resistivity of less than about 20,000 ohm-cm.
  • the backfill will most always be applied to the anode-containing slots 11 and the current feeder-containing slots 13 in sufficient amount to fill the slots 11 and 13 at least flush with the reinforced concrete surface.
  • the applied material will be sufficient to completely embed the anodes 32.
  • complete coverage of the anode ribbons and current feeder will ensue. If portions of the current feeders extend beyond the surface, e.g., down below a bridge deck, such portions of the current feeders need not be so embedded in backfill.
  • the anode ribbon system can be serviceable where an overlay will be included in he finishing operation. Such overlay may be any of those which are useful in the operation of providing an overlay to a reinforced concrete structure.
  • the anode ribbons may be placed, as in flat surface mounting, in non-slotted application to a reinforced concrete structure, e.g., a bridge or building support column. Such application may be especially serviceable for application in a vertical plane.
  • the anode ribbons in such surface mounting can be as parallel strips, or spiraled around a column, or in arcuate or zig zag or other shapes. Aspects of dimensions and spacings for both anode ribbons and current feeders are as have been discussed hereinbefore.
  • the anode ribbons can be uncoiled onto the concrete surface, fastened by any means suitable for fastening metal anodes to concrete, and then overlaid, all as has been discussed hereinabove.
  • the current feeders are electrically connected to the positive pole of a suitable power supply, and the reinforcing steel of the concrete structure is connected to the negative pole of the power supply.
  • a direct current suitable for the cathodic protection of the reinforcing steel is then applied. It is contemplated that any power source suitable for use with the cathodic protection of assemblies for use in protecting concrete such as in bridge decks and parking garages and the like, will be useful in the present invention.
  • the ribbons for both the anode ribbons and the current feeders will be valve metal ribbons.
  • metals of the ribbons and current feeders will be titanium, tantalum, zirconium or niobium.
  • the suitable metals of the ribbons and feeders can include alloys of these metals with themselves and other metals as well as their intermetallic mixtures.
  • corrosion resistance e.g., resistance to corrosion in a chloride contaminated concrete environment, and also for its availability
  • titanium As representative of such serviceable metals is Grade 1 titanium, an annealed titanium of low embrittlement.
  • Such feature is advantageous for providing for ribbon installation without deleterious ribbon breakage.
  • alloying may add to the embrittlement of an elemental metal and thus suitable alloys may have to be carefully selected.
  • the metal ribbons can be prepared directly from the selected metal such as by slitting a sheet or coil of valve metal into desired widths of ribbon, with the sheet or coil itself providing the desirable ribbon thickness. Slitters can be useful in preparing the metal ribbons. After slitting, the resulting ribbon can be readily rolled into coiled configuration, such as for storage or transport for further operation.
  • the anode ribbons can be coated as a final step in their preparation. This coating may be applied to both flat faces of the ribbon anode, as well as the anode edges, e.g., by initial immersion of the ribbon anode into coating composition. Such can be particularly serviceable when the anode will be used on edge, either in slots or at the concrete surface. Where the ribbon anode will be mounted on the surface but installed flat to the surface, it is contemplated that for some installations only the flat face of the ribbon anode facing the concrete surface needs to have the active coating. It is to be understood that the ribbons may also be coated before they are in ribbon form whereby on forming, e.g., cutting, the ribbon widths will bear coating but the ribbon thicknesses will not.
  • the substrate can be particularly useful for bearing a catalytic active material, thereby forming a catalytic structure.
  • the ribbon substrate can have a catalyst coating, resulting in an anode structure.
  • the valve metal ribbon will be subjected to a cleaning operation, e.g., a degreasing operation, which can include cleaning plus etching, as is well known in the art of preparing a valve metal to receive an electrochemically active coating.
  • a cleaning operation e.g., a degreasing operation, which can include cleaning plus etching, as is well known in the art of preparing a valve metal to receive an electrochemically active coating.
  • a valve metal which may also be referred to herein as a "film-forming" metal, will not function as an anode without an electrochemically active coating which prevents passivation of the valve metal surface.
  • This electrochemically active coating may be provided from platinum or other platinum group metal, or it may be any of a number of active oxide coatings such as the platinum group metal oxides, magnetite, ferrite, cobalt spinel, or mixed metal oxide coatings, which have been developed for use as anode coatings in the industrial electrochemical industry. It is particularly preferred for extended life protection of concrete structures that the anode coating be a mixed metal oxide, which can be a solid solution of a film-forming metal oxide and a platinum group metal oxide.
  • the coating should be present in an amount of from about 0.025 to about 0.5 gram of active coating per square meter of valve metal ribbon.
  • Less than about 0.025 gram of active coating, e.g., of platinum group metal will provide insufficient electrochemically active coating to serve for preventing passivation of the valve metal substrate over extended time, or to economically function at a sufficiently low single electrode potential to promote selectivity of the anodic reaction.
  • the presence of greater than about 0.5 gram of active coating, or more often of greater than about 0.25 gram of platinum group metal, per square meter of the valve metal ribbon can contribute an expense without commensurate improvement in anode lifetime.
  • the mixed metal oxide coating is highly catalytic for the oxygen evolution reaction, and at low current densities in a chloride contaminated concrete environment, will evolve no chlorine or hypochlorite.
  • the platinum group metal or mixed metal oxides for the coating are such as have generally been described in one or more of U.S. Patent Nos. 3,265,526, 3,632,498, 3,711,385 and 4,528,084. More particularly, such platinum group metals include platinum, palladium, rhodium, iridium and ruthenium or alloys of themselves and with other metals.
  • Mixed metal oxides include at least one of the oxides of these platinum group metals in combination with at least one oxide of a valve metal or another non-precious metal. It is preferred for economy that the coatings be such as have been disclosed in the U.S. Patent No. 4,528,084.
  • the anode ribbon 2 will be connected to a current feeder 4, e.g., the metal strip current feeder 4 of Fig. 4.
  • a current feeder 4 will most always be a valve metal and preferably is the same metal including alloy or intermetallic mixture, as the metal most predominantly found in the valve metal anode ribbon 2.
  • This current feeder 4 must be firmly affixed to the metal anode ribbon 2.
  • Such a manner of firmly fixing the feeder 4 to the ribbon 2 can be by welding, as has been discussed hereinabove. Moreover, the welding can proceed through the coating.
  • a coated ribbon current feeder 4 can be pressed against a coated anode ribbon 2 with coated faces of each in contact, and yet the welding can readily proceed.
  • the ribbon current feeder 4 can be sufficiently welded to the anode ribbon 2 to provide uniform distribution of current thereto.
  • the embedded portion of current feeders 4 may also be coated, such as with the same electrochemically active coating of the anode ribbon 2, but most always the current feeders 4 will be left uncoated. If coated, like considerations for the coating weight, such as for the anode ribbon 2, are also important for the current feeders 4.
  • These feeders 4 may be attached to the anode ribbon 2 before or after coating.
  • Such current feeders 4 can then connect outside of the concrete environment to a current conductor, which current conductor being external to the concrete need not be so coated.
  • the current feeder may include a bar extending through a hole to the underside of the deck surface and extending upwardly to where a strip current feeder 4 is located. In this way, mechanical current connections can be made external to the finished concrete structure, and are thereby readily available for access and service if necessary. Connections to a current distribution bar external to the concrete may be of conventional mechanical means such as a bolted spade-lug connector.

Landscapes

  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Prevention Of Electric Corrosion (AREA)

Claims (30)

1. Kathodisches Schutzsystem mit angelegtem Strom für stahlbewehrten Beton, das:
a) eine dünne und längliche, korrosionsbeständige Ventilmetallbandanode mit einem elektrochemisch aktiven Oberflächenüberzug, einem zumindest im wesentlichen rechteckigen Querschnitt, einer Breite innerhalb des Bereichs von etwa 0,25 bis etwa 2,5 cm, einer Dicke innerhalb des Bereichs von etwa 0,02 bis etwa 0,15 cm und einem Breite/Dicke-Verhältnis innerhalb des Bereichs von etwa 20:1 bis etwa 5:1, womit sie eine Bandbreite aufweist, die im wesentlichen größer ist als ihre Dikke, während sie außerdem eine Bandlänge aufweist, die im wesentlichen größer ist als ihre Breite, und auf einer Betonoberfläche oder innerhalb von Schlitzen in einer Betonoberfläche installiert ist, aber mit Abstand von Stahlbewehrungselementen in dem Beton angeordnet ist;
b) ein korrosionsbeständiges Ventilmetallstromverteilungselement, das elektrisch mit der Bandanode verbunden ist und eine größere Masse pro Längeneinheit aufweist als die Bandanode, und
c) eine Leiste oder Schicht aus ionisch leitfähigem, nicht aus Kohlenstoff bestehendem, zementartigem Material umfaßt, in das die Bandanode an der Betonoberfläche eingebettet ist und das einen Volumenwiderstand von weniger als 50 000 Ohm-cm aufweist.
2. Kathodisches Schutzsystem nach Anspruch 1, bei dem mehrere Bandanoden auf oder in einer Betonoberfläche im wesentlichen parallel mit Abstand voneinander angeordnet sind und mit einem gemeinsamen Stromverteilungselement verbunden sind.
3. Kathodisches Schutzsystem nach Anspruch 1 oder 2, bei dem die Bandanode auf einer horizontalen, geneigten, senkrechten oder überkopf angeordneten Betonoberfläche installiert ist.
4. Kathodisches Schutzsystem nach Anspruch 3, bei dem eine Bandfläche der installierten Bandanoden auf der Betonoberfläche aufliegt, die Anoden so in einer Leiste von zementartigem Material eingebettet und mit Abstand voneinander angeordnet sind, daß die Leiste aus zementartigem Material nicht die ganze Betonoberfläche bedeckt.
5. Kathodisches Schutzsystem nach Anspruch 3, bei dem eine Bandfläche der installierten Bandanode auf der Betonoberfläche aufliegt und das aufgebrachte zementartige Material eine Schicht ist, die die Bandanode einbettet und die ganze Betonoberfläche bedeckt.
6. Kathodisches Schutzsystem nach Anspruch 1 oder 2, bei dem die Bandanode in einer Schlitzfräsung in der Oberfläche des Betons installiert ist und der Schlitz nicht tiefer als etwa 4 cm und nicht breiter als etwa 1,25 cm ist und mit dem ionisch leitfähigen, zementartigen Material gefüllt ist.
7. Kathodisches Schutzsystem nach Anspruch 6, das eine Vielzahl von benachbarten Schlitzen umfaßt, die die Ventilmetallbänder enthalten und in einem Abstand innerhalb des Bereichs von etwa 15 bis etwa 60 cm voneinander angeordnet sind.
8. Kathodisches Schutzsystem nach Anspruch 6 oder 7, bei dem der (die) die Bandanode enthaltende(n), gefüllte(n) Schlitz(e) mit einer Betonauflage überzogen ist/sind.
9. Kathodisches Schutzsystem nach einem der vorhergehenden Ansprüche, bei dem das zementartige Material einen Volumenwiderstand von weniger als etwa 20 000 Ohm-cm aufweist und ein nicht-schrumpfender, selbst-nivelierender pumpbarer Vergußmörtel ist.
10. Kathodisches Schutzsystem nach einem der vorhergehenden Ansprüche, bei dem die Ventilmetallbandanode und das Ventilmetallstromverteilungselement aus Metall ausgewählt aus Titan, Tantal, Zirkon, Niob, deren Legierungen und intermetallischen Mischungen hergestellt sind.
11. Kathodisches Schutzsystem nach einem der vorhergehenden Ansprüche, bei dem die Bandanode mit dem Stromverteilungselement elektrisch widerstandsverschweißt ist und die Anode und das Element in Fläche-an-Fläche-Kontakt stehen.
12. Kathodisches Schutzsystem nach Anspruch 11, bei dem das elektrisch mit der Bandanode verbundene Stromverteilungselement keinen elektrochemisch aktiven Oberflächenüberzug aufweist.
13. Kathodisches Schutzsystem nach einem der vorhergehenden Ansprüche, bei dem das Stromverteilungselement ein längliches Element mit zumindest im wesentlichen rechteckigem Querschnitt, einer Breite nicht größer als 0,3 cm und einer Breite im Verhältnis zur Breite der Bandanode, die innerhalb des Bereichs von etwa 3:1 bis etwa 1,1:1 liegt.
14. Kathodisches Schutzsystem nach einem der vorhergehenden Ansprüche, bei dem das Stromverteilungselement zumindest teilweise in eine Schlitzfräsung in der Oberfläche des Betons eingesetzt ist, wobei benachbarte, die Stromverteilungselemente aufnehmende Schlitze in einem Abstand innerhalb des Bereichs von etwa 25 bis etwa 100 m voneinander angeordnet sind.
15. Kathodisches Schutzsystem nach einem der vorhergehenden Ansprüche, bei dem die Ventilmetall-anode einen elektrochemisch aktiven Oberflächenüberzug aufweist, der ein Metall oder ein Oxid eines Metalls der Platingruppe umfaßt und etwa 0,025 bis etwa 1,5 g katalytisches Metall pro m² Bandanode enthält.
16. Kathodisches Schutzsystem nach Anspruch 15, bei dem der elektrochemisch aktive Oberflächenüberzug mindestens ein Oxid ausgewählt aus Oxiden der Metalle der Platingruppe, Magnetit, Ferrit und Kobaltoxidspinell umfaßt.
17. Kathodisches Schutzsystem nach Anspruch 15, bei dem der elektrochemisch aktive Oberflächenüberzug ein Mischkristallmaterial aus mindestens einem Oxid eines Ventilmetalls und mindestens einem Oxid eines Metalls der Platingruppe umfaßt.
18. Kathodisches Schutzsystem nach Anspruch 3, 4 oder 5 oder einem der Ansprüche 9 bis 17, wenn abhängig von Anspruch 3, 4 oder 5, bei dem das Anodenband im wesentlichen um 180° um sich selbst zurückgebogen ist und an der Biegung in einer senkrecht zur Längsachse des Bandes verlaufenden Richtung gedreht ist, um in seiner Installationsebene auf dem Beton abrupte Anodenecken zu liefern, wobei die Anode beispielsweise entlang ihrer Längsachse um einem Winkel bis 90° gedreht ist.
19. Kathodisches Schutzsystem nach einem der vorhergehenden Ansprüche, bei dem das Stromverteilungselement mit einer Energiequelle verbunden ist, die auf die Bandanode einen Betriebsstrom von etwa 50 bis etwa 600 mA/m² aufdrückt.
20. Verfahren zum Installieren eines kathodischen Schutzsystems gemäß Anspruch 1, bei dem:
a) auf einer Betonoberfläche oder in Schlitzen in einer Betonoberfläche eine dünne und längliche, korrosionsbeständige Ventilmetallbandanode gemäß Anspruch 1 mit bestand von Stahlbewehrungselementen in dem Beton angebracht wird,
b) die Anode mit dem korrosionsbeständigen Ventilmetallstromverteilungselement elektrisch verbunden wird und
c) die Leiste oder Schicht aus leitfähigem, zementartigem Material zur Einbettung der Bandanode in dem zementartigen Material auf die Betonoberfläche aufgebracht wird.
21. Verfahren nach Anspruch 20, bei dem mehrere Bandanoden auf oder in einer Betonoberfläche im wesentlichen parallel mit bestand voneinander angebracht und mit einem gemeinsamen Stromverteilungselement verbunden werden.
22. Verfahren nach Anspruch 20 oder 21, bei dem die Bandanode an einer horizontalen, geneigten, senkrechten oder überkopf angeordneten Betonoberfläche angebracht wird.
23. Verfahren nach Anspruch 22, bei dem die Bandanode flach auf der Betonoberfläche angebracht wird und eine Leiste von zementartigem Material zur Einbettung der Bandanode aufgebracht wird, ohne die ganze Betonoberfläche zu bedecken.
24. Verfahren nach Anspruch 20 oder 21, bei dem die Bandanode in eine Schlitzfräsung in der Oberfläche des Betons eingesetzt wird.
25. Verfahren nach Anspruch 24, bei dem die Bandanode anfangs in einen Schlitz eingesetzt wird, das Stromverteilungselement eingesetzt wird, der Teil der Bandanode, der dem Stromverteilungselement benachbart ist, aus dem Schlitz entfernt wird und mit dem Stromverteilungselement elektrisch verbunden wird und die resultierende verbundene Bandanode in den Schlitz zurückgeführt wird.
26. Verfahren nach einem der Ansprüche 20 bis 25, bei dem die an der Betonoberfläche angebrachte Bandanode mit dem Stromverteilungselement elektrisch widerstandsverschweißt wird.
27. Verfahren nach einem der Ansprüche 20 bis 26, bei dem das auf die Bandanode aufgebrachte zementartige Material ein pumpbarer Vergußmörtel mit einem Volumenwiderstand von weniger als etwa 20 000 Ohm-cm ist.
28. Verfahren nach einem der Ansprüche 20 bis 27, bei dem die Bandanode um sich selbst um zumindest im wesentlichen 180° zurückgebogen wird und an der Biegung in eine senkrecht zur Längsachse des Bandes angeordnete Richtung gedreht wird, um in ihrer Installationsebene auf dem Beton abrupte Anodenecken zu liefern, wobei das Anodenband während des Anbringens an dem Beton beispielsweise entlang seiner Längsachse um einen Winkel bis 90° gedreht wird.
29. Verfahren zum kathodischen Schützen einer stahlbewehrten Betonstruktur unter Verwendung des kathodischen Schutzsystems gemäß einem der Ansprüche 1 bis 19 oder installiert nach dem Verfahren gemäß einem der Ansprüche 20 bis 28, bei dem das Stromverteilungselement mit einer Energiequelle verbunden wird, die auf die Bandanode einen Betriebsstrom von etwa 50 bis etwa 600 mA/m² aufdrückt.
30. Stahlbewehrte Betonstruktur, die kathodisch durch das System gemäß einem der Ansprüche 1 bis 19 geschützt ist.
EP88810287A 1987-05-08 1988-05-04 System mit Band-Anode für den kathodischen Schutz von stahlarmiertem Beton Expired EP0292428B1 (de)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AT88810287T ATE72840T1 (de) 1987-05-08 1988-05-04 System mit band-anode fuer den kathodischen schutz von stahlarmiertem beton.
SA92130118A SA92130118B1 (ar) 1987-05-08 1992-09-19 نظام اذود شريطي anode ribbon للوقاية الكاثودية cathodic protection للخرسانة المسلحة بالصلب

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US4780687A 1987-05-08 1987-05-08
US17842288A 1988-04-20 1988-04-20
US178422 1988-04-20
US47806 1997-05-27

Publications (3)

Publication Number Publication Date
EP0292428A2 EP0292428A2 (de) 1988-11-23
EP0292428A3 EP0292428A3 (en) 1989-05-10
EP0292428B1 true EP0292428B1 (de) 1992-02-26

Family

ID=26725450

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88810287A Expired EP0292428B1 (de) 1987-05-08 1988-05-04 System mit Band-Anode für den kathodischen Schutz von stahlarmiertem Beton

Country Status (10)

Country Link
EP (1) EP0292428B1 (de)
JP (1) JPS6452090A (de)
AU (1) AU608837B2 (de)
CA (1) CA1325789C (de)
DE (1) DE3868535D1 (de)
ES (1) ES2030206T3 (de)
GR (1) GR3003900T3 (de)
HK (1) HK71092A (de)
SA (1) SA92130118B1 (de)
SG (1) SG74592G (de)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5183694A (en) * 1988-04-19 1993-02-02 Webb Michael G Inhibiting corrosion in reinforced concrete
GB9015743D0 (en) * 1990-07-17 1990-09-05 Pithouse Kenneth B The protection of cementitious material
WO1992002664A1 (en) * 1990-08-10 1992-02-20 Nakagawa Corrosion Protecting Co., Ltd. Anode member to be electrically charged for preventing corrosion of reinforced concrete and electric corrosion preventive method employing said member
CA2144775A1 (en) * 1992-09-18 1994-03-31 Chameleon Investments Limited A continuous-action reference electrode for the cathodic protection of metallic structures
US5650060A (en) * 1994-01-28 1997-07-22 Minnesota Mining And Manufacturing Company Ionically conductive agent, system for cathodic protection of galvanically active metals, and method and apparatus for using same

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AR201314A1 (es) * 1973-04-19 1975-02-28 Bagnulo L Anodo de sacrificio para la proteccion catodica de cualquier tipo de superficie metalica
US4255241A (en) * 1979-05-10 1981-03-10 Kroon David H Cathodic protection apparatus and method for steel reinforced concrete structures
JPS5838513A (ja) * 1981-08-31 1983-03-07 株式会社タチエス 車両用シ−ト支持体
GB2140456A (en) * 1982-12-02 1984-11-28 Taywood Engineering Limited Cathodic protection
JPS6039157A (ja) * 1983-08-12 1985-02-28 Hitachi Ltd 非晶質磁性合金の製造方法

Also Published As

Publication number Publication date
SG74592G (en) 1992-10-02
GR3003900T3 (de) 1993-03-16
EP0292428A3 (en) 1989-05-10
EP0292428A2 (de) 1988-11-23
HK71092A (en) 1992-09-25
CA1325789C (en) 1994-01-04
DE3868535D1 (de) 1992-04-02
JPH0431031B2 (de) 1992-05-25
SA92130118B1 (ar) 2004-09-01
DE3868535A1 (de) 1992-04-02
AU608837B2 (en) 1991-04-18
JPS6452090A (en) 1989-02-28
ES2030206T3 (es) 1992-10-16
AU1560288A (en) 1988-11-10

Similar Documents

Publication Publication Date Title
US4900410A (en) Method of installing a cathodic protection system for a steel-reinforced concrete structure
US5639358A (en) Cathodic protection system for a steel-reinforced concrete structure
EP0222829B1 (de) Kathodisches schutzsystem für eine stahlarmierte betonstruktur und verfahren zur installierung
CA2880235C (en) Galvanic anode and method of corrosion protection
EP0407348A1 (de) Netzanode und Netzseparator zur Verwendung mit Stahlbeton
EP0292428B1 (de) System mit Band-Anode für den kathodischen Schutz von stahlarmiertem Beton
RU2416678C2 (ru) Дискретный анод для катодной защиты железобетона
EP0458951B1 (de) Neue elektroden und kathodisches schutzsystem
EP0534392B1 (de) Anodenkonstruktion für den kathodischen Schutz von stahlverstärktem Beton und relevante Methode zu seiner Verwendung
US5098543A (en) Cathodic protection system for a steel-reinforced concrete structure
CA2236650C (en) Louvered anode for cathodic protection systems
US4880517A (en) Catalytic polymer electrode for cathodic protection and cathodic protection system comprising same
US5423961A (en) Cathodic protection system for a steel-reinforced concrete structure
CA2302966C (en) Ladder anode for cathodic protection
US5200259A (en) Fiber-filled concrete overlay in cathodic protection
GB2590149A (en) Protected reinforced concrete structure
NO170291B (no) Katodisk beskyttet, staalarmert betongkonstruksjon og fremgangsmaate for aa installere en belagt ventilmetallelektrodei et katodisk beskyttelsessystem for en slik konstruksjon

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE CH DE ES FR GB GR IT LI LU NL SE

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT BE CH DE ES FR GB GR IT LI LU NL SE

17P Request for examination filed

Effective date: 19890511

17Q First examination report despatched

Effective date: 19900705

ITF It: translation for a ep patent filed
GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE ES FR GB GR IT LI LU NL SE

REF Corresponds to:

Ref document number: 72840

Country of ref document: AT

Date of ref document: 19920315

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3868535

Country of ref document: DE

Date of ref document: 19920402

ET Fr: translation filed
REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2030206

Country of ref document: ES

Kind code of ref document: T3

REG Reference to a national code

Ref country code: GR

Ref legal event code: FG4A

Free format text: 3003900

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GR

Payment date: 19940421

Year of fee payment: 7

EPTA Lu: last paid annual fee
EAL Se: european patent in force in sweden

Ref document number: 88810287.8

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GR

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19951130

REG Reference to a national code

Ref country code: GR

Ref legal event code: MM2A

Free format text: 3003900

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

REG Reference to a national code

Ref country code: CH

Ref legal event code: NV

Representative=s name: CRONIN INTELLECTUAL PROPERTY

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20060531

Year of fee payment: 19

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: LU

Payment date: 20070326

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 20070410

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20070412

Year of fee payment: 20

REG Reference to a national code

Ref country code: CH

Ref legal event code: PCAR

Free format text: CRONIN INTELLECTUAL PROPERTY;CHEMIN DE PRECOSSY 31;1260 NYON (CH)

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 20070420

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 20070503

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: ES

Payment date: 20070522

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 20070531

Year of fee payment: 20

Ref country code: DE

Payment date: 20070531

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20070410

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20070503

Year of fee payment: 20

REG Reference to a national code

Ref country code: GB

Ref legal event code: PE20

Expiry date: 20080503

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

BE20 Be: patent expired

Owner name: *ELTECH SYSTEMS CORP.

Effective date: 20080504

NLV7 Nl: ceased due to reaching the maximum lifetime of a patent

Effective date: 20080504

EUG Se: european patent has lapsed
REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20080505

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20080505

Ref country code: NL

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20080504

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20080503

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20070504